Calculation device

Abstract

A calculation device (10) according to the present disclosure comprises: a calculation unit (12) that, when the depth of a crack generated in a structure (1) by a first load is defined as h1, the depth of the structure (1) in a crack direction is defined as a, the depth of a crack generated in the structure (1) by a (k−1)-th load on the structure (1) is defined as hk−1, and the depth of a crack generated in the structure (1) by a k-th load on the structure is defined as hk, calculates, by the following equation, a total hsum of the depths of cracks generated in the structure (1) by repeating the load n times on the structure (1); and an output unit (13) for outputting the calculated total hsum of the crack depths.

Description

computing device

[0001] The present disclosure relates to computing devices.

[0002] In recent years, there has been a demand for efficient evaluation of the strength of structures such as reinforced concrete manholes. One of the reasons for this is the aging of structures that were built in large numbers during Japan's period of rapid economic growth. Another reason is the decline in the working population due to a declining birthrate and aging population. To address these issues, it is necessary to consider how to efficiently maintain aging structures.

[0003] In order to grasp the bearing capacity of a structure, structural calculations based on knowledge of structural mechanics are generally performed. There are various methods and tools for structural calculations, but in recent years, methods using the finite element method (FEM) have become more popular (see, for example, Non-Patent Document 1).

[0004] Structural analysis using FEM makes it possible to understand how a structure will behave under various loads. By applying loads that simulate real-world conditions, the strength of the structure can be evaluated, and this can be used in the design and maintenance of the structure.

[0005] Repeated loads are a type of load that simulates a real-world environment. For example, an underground structure beneath a roadway is subjected to a load each time a vehicle passes by. Repeated loads on structures can also be analyzed using FEM.

[0006] P. Chaimahawan, A Pimanmas, “Nonlinear FEM Analysis of RC Beam-Column Joint Strengthened byCast In-Situ Joint Expansion”, Journal of Advanced Concrete Technology Vol. 7, No. 3, 307-326, (2009)

[0007] In FEM analysis of repeated loads on a structure, structural calculations must be performed for each repetition of the load. In a real environment, for example, depending on the location, vehicles may pass through the structure several thousand times in a single day. In this case, several thousand loads are applied repeatedly.

[0008] The calculation time required for FEM analysis depends on the analysis conditions, such as the specifications of the computer used and the shape of the structure being analyzed, but in the case of nonlinear analysis that can reproduce cracks in a structure due to load, each analysis often takes, for example, several tens of minutes.

[0009] When reproducing the progression of cracks in a structure due to repeated loads using FEM analysis, nonlinear analysis is performed repeatedly. However, performing nonlinear analysis thousands of times requires the use of a highly sophisticated computer or the execution of the analysis requires a huge amount of processing time, which is generally not practical.

[0010] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a calculation device that can more easily calculate the depth of cracks that occur in structures due to repeated loads.

[0011] In order to solve the above problem, the calculation device according to the present disclosure is a calculation device that calculates the depth of a crack that occurs in a structure due to repeated application of the same load to the structure, and calculates the depth h of a crack that occurs in the structure due to the first load. １ The depth of the crack in the direction of the crack in the structure is a, and the depth of the crack that occurs in the structure due to the k-1th load on the structure is h. ｋ－１ The depth of the crack that occurs in the structure due to the kth load on the structure is defined as h ｋ Then, the total depth of cracks that occur in the structure due to repeated n loads on the structure can be calculated using the following formula: ｓｕｍ A calculation unit that calculates the sum of the calculated crack depths h ｓｕｍ and an output unit that outputs the signal.

[0012] According to the calculation device of the present disclosure, it is possible to more easily calculate the depth of cracks that occur in a structure due to repeated loads.

[0013] FIG. 2 is a diagram for explaining cracks that occur in a structure due to repeated loads. FIG. 3 is a diagram for explaining cracks that occur in a structure due to repeated loads. FIG. 4 is a diagram for explaining cracks that occur in a structure due to repeated loads. FIG. 5 is a diagram showing an example of the configuration of a calculation device according to an embodiment of the present disclosure. FIG. 6 is a flowchart showing an example of the operation of the calculation device shown in FIG. 2. FIG. 7 is a flowchart showing another example of the operation of the calculation device shown in FIG. 2. FIG. 8 is a diagram showing a calculation of h by the calculation device shown in FIG. 2 and a conventional method. ｓｕｍ Fig. 1 is a diagram showing an example of a calculation result of Fig. 2. Fig. 2 is a diagram showing an example of the type, weight, and number of times of passage of vehicles passing through a road. Fig. 3 is a diagram showing an example of the configuration of a computer that functions as a calculation device according to the present disclosure.

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0015] 1A to 1C, we will explain the progression of cracks in structure 1 due to repeated loads. In the following, we will assume that a load of the same magnitude is repeatedly applied to structure 1 in one direction (in FIG. 1A, the vertical direction on the page).

[0016] As shown in FIG. 1A, when a first load P1 is applied to the structure 1, as shown in FIG. 1B, a depth h １ In the following, as shown in Figure 1B, the width of the structure 1 in the direction in which the crack progresses is defined as a, and the width of the structure 1 in the direction perpendicular to the load application direction and the direction in which the crack progresses (the depth direction in Figure 1B) is defined as b.

[0017] Depth h １ As shown in FIG. 1B, a second load P2 was applied to the structure 1 in which the cracks of depth h ２ In other words, a total of cracks of depth h １ +h ２ Cracks occur.

[0018] Depth h １ +h ２ As shown in Figure 1C, a third load P3 is applied to the structure 1 in which a crack has occurred. Consider the repetition of load application in this way, i.e., the case where the n-1th load Pn-1 is applied and the case where the nth load Pn is applied. When the n-1th load Pn-1 is applied to the structure 1, the structure 1 is subjected to the loads up to the n-2th load. １ +h ２ +...h ｎ－２ In addition, when the nth load Pn is applied, the structure 1 is subjected to the loads up to the n-1th time, resulting in a crack of depth h １ +h ２ +...h ｎ－２ +h ｎ－１ There are cracks of depth.

[0019] Stress σ applied to structure 1 when the n-1th load Pn-1 is applied ｎ－１ , and the stress σ applied to the structure 1 when the nth load Pn is applied. ｎ are respectively expressed by the following equations (1) and (2).

[0020] Since the depth to which the crack advances is proportional to the magnitude of the stress, the following equation (3) holds true.

[0021] Since it is assumed that equations (1) and (2) are substituted into equation (3) and equal loads are repeatedly applied, Pn-1 = Pn, and therefore equation (3) is expressed as the following equation (4).

[0022] From equation (4), the total depth of cracks due to repeated loading up to the nth time is h ｓｕｍ is expressed by the following equation (5).

[0023] From equation (5), the crack depth h of the structure 1 due to the first load P1 is １ and the total depth of the cracks due to repeated loads up to the nth time from the width a of the structure 1 in the direction of crack propagation h ｓｕｍ It turns out that it is possible to calculate

[0024] Next, a configuration of a computing device 10 according to an embodiment of the present disclosure will be described with reference to Fig. 2. Fig. 2 is a diagram illustrating an example of a configuration of a computing device 10 according to an embodiment of the present disclosure. The computing device 10 according to the present disclosure calculates the total depth h of cracks that occur in a structure 1, such as a concrete structure, due to repeated application of the same load to the structure 1. ｓｕｍ It calculates the following.

[0025] As shown in FIG. 2, the calculation device 10 according to this embodiment includes an input unit 11, a calculation unit 12, and an output unit 13.

[0026] The input unit 11 calculates the total depth h of cracks that occur in the structure 1 due to repeated loads. ｓｕｍ Specifically, the input unit 11 receives input of the width a of the structure 1 in the direction of crack propagation in the structure 1 due to the load, and the number of repeated loads n. The input unit 11 also receives input of the depth h of the crack that occurs in the structure 1 due to the first load. １ , or the magnitude P of the load per one time. The input unit 11 outputs the input information to the calculation unit 12.

[0027] The calculation unit 12 calculates the total depth h of cracks that occur in the structure 1 due to n repeated loads based on the information input via the input unit 11. ｓｕｍ Specifically, the calculation unit 12 calculates the depth h of the crack that occurs in the structure 1 due to the first load. １ The depth of the crack in the direction of the crack in the structure 1 is a, and the depth of the crack that occurs in the structure 1 due to the k-1th load on the structure 1 is h. ｋ－１ The depth of the crack that occurs in the structure 1 due to the kth load on the structure 1 is h ｋ Then, the total depth of cracks that occur in the structure 1 due to repeated n loads on the structure 1 can be calculated by the above-mentioned formula (5): ｓｕｍ Calculate.

[0028] The calculation unit 12 calculates the depth h of the crack that occurs in the structure 1 due to the first load. １ If is entered, the total crack depth h is calculated using the entered value. ｓｕｍFurthermore, when the magnitude P of the load per load is input, the calculation unit 12 calculates the depth h of the crack that occurs in the structure 1 due to the first load based on the magnitude P of the load per load by analysis using FEM or the like. １ Then, the calculation unit 12 calculates the depth h of the crack that occurs in the structure 1 due to the calculated first load. １ Using the total crack depth h ｓｕｍ Calculate.

[0029] The calculation unit 12 outputs the calculation result to the output unit 13 .

[0030] The output unit 13 outputs the sum h of the depths of cracks that occur in the structure 1 due to the repeated application of the load n times, calculated by the calculation unit 12. ｓｕｍ is outputted, for example, by being displayed on a display device.

[0031] Next, an operation of the computing device 10 according to this embodiment will be described. Fig. 3A is a flowchart showing an example of the operation of the computing device 10 according to this embodiment, and is a diagram for explaining a calculation method by the computing device 10.

[0032] The input unit 11 receives the number of repeated loads n, the width a of the structure 1 in the direction of crack propagation due to the load, and the depth h of the crack generated in the structure 1 due to the first load. １ The input of the depth h of the crack generated in the structure 1 by the first load is received (step S11). １ can be determined experimentally, for example.

[0033] The calculation unit 12 calculates the number of repeated loads n, the width a of the structure 1 in the direction of crack propagation due to the load, and the depth h of the crack generated in the structure 1 due to the first load. １ Based on the above formula (5), the total depth of cracks that occur in the structure 1 due to repeated loading n times is calculated as h ｓｕｍ is calculated (step S12).

[0034] The output unit 13 outputs the calculation results of the calculation unit 12 by displaying them on a display device (step S13).

[0035] 3B is a diagram showing another example of the operation of the computing device 10 according to this embodiment. In FIG. 3B, the same processes as those in FIG. 3A are denoted by the same reference numerals, and the description thereof will be omitted.

[0036] The input unit 11 receives input of the number of load repetitions n, the width a of the structure 1 in the direction of crack propagation in the structure 1 due to the load, and the magnitude P of the load per repetition (step S21).

[0037] The calculation unit 12 calculates the depth h of the crack that occurs in the structure 1 due to the first load based on the magnitude P of the load per load that is input. １ The calculation unit 12 calculates the depth h of the crack generated in the structure 1 by the first load, for example, by an analysis such as FEM. １ Calculate the depth h of the crack that occurs in structure 1 due to the first load. １ After calculating the value of the total depth of cracks generated in the structure 1 due to the repeated application of the load n times, the calculation unit 12 proceeds to the processing of step S12. ｓｕｍ Calculate.

[0038] For example, the total depth of cracks that occur in the structure 1 after 50 repeated loads is h ｓｕｍ In order to calculate the crack depth, the conventional method of calculating the crack depth for each load requires 50 analyses. If each analysis takes, for example, 30 minutes, it would take 25 hours to perform 50 analyses.

[0039] On the other hand, in the calculation device 10 according to this embodiment, the depth h of the crack caused by the first load is calculated as １ If this is known, the total depth of cracks that will occur in structure 1 due to 50 repeated loads can be calculated from equation (5). ｓｕｍ For example, the depth of the crack caused by the first load can be calculated from the magnitude of the load P per load. １When calculating by analysis, the calculation device 10 according to this embodiment only requires one analysis. That is, the time required for the analysis is 30 minutes, which is shorter than the processing time required by conventional methods. Furthermore, the number of analyses that require a high-spec computer can be reduced, thereby reducing operating costs.

[0040] The total depth of cracks that occur in the structure 1 due to n repeated loads is h ｓｕｍ One possible method of calculating (a) is to multiply the depth of a crack that occurs in the structure 1 due to a single load by the number of repetitions n (comparative method). However, as shown in Figures 1A to 1C, as the crack progresses due to repeated loading, the area of ​​the crack-free parts of the structure 1 decreases, and stress due to the load is concentrated in those parts. As a result, it is thought that the depth of the crack due to a single load increases as the number of repetitions increases. The comparative method does not take this stress concentration into account, resulting in lower accuracy of the calculation results.

[0041] FIG. 4 shows the total depth h of cracks generated in the structure 1 by n repeated loads, calculated by the calculation method using the calculation device 10 according to the present embodiment (the calculation method according to the present disclosure) and the comparative method. ｓｕｍ In FIG. 4, the magnitude of the load per load P=1, and the depth of the crack in the structure 1 due to the first load h １ = 1, width of structure 1 in the crack direction a = 100, and number of load repetitions n = 50.

[0042] As shown in Figure 4, in the comparative method, the total depth of the cracks h ｓｕｍ increases linearly. On the other hand, in the calculation method according to the present disclosure, the crack depth due to the load per cycle increases as the number of cycles increases. Therefore, in the calculation method according to the present disclosure, a more accurate total crack depth h is calculated, taking into account stress concentration due to a decrease in the area of ​​the non-cracked portion of the structure 1. ｓｕｍ It becomes possible to calculate

[0043] If the structure 1 is, for example, a manhole, its size is standardized. Therefore, accurate data exists for the width a of the structure 1 in the crack direction, the width b of the structure 1 in the direction perpendicular to the load direction and the crack propagation direction, and the tensile strength. Therefore, the total depth h of the crack ｓｕｍ Although a manhole has been used as an example, even when the structure 1 is something other than a manhole, the Ministry of Land, Infrastructure, Transport and Tourism or a standards organization often specifies the size and material of the structure 1. Therefore, such specified data can be used to calculate the total crack depth h ｓｕｍ can be used to calculate

[0044] The total depth of cracks in the actual environment of structure 1 h ｓｕｍ In order to calculate the above, it is necessary to appropriately set the magnitude P of the load applied to the structure 1 and the number of repetitions n of the load. Below, a method for setting the magnitude P of the load applied to the structure 1 and the number of repetitions n of the load will be described.

[0045] Most of the structures 1 are installed outdoors. One possible environment in which such a structure 1 is subjected to repeated loads is an environment in which the structure 1 is buried under a road. Various vehicles, such as heavy trucks and lightweight minicars, travel on the road. Since the weights of the vehicles traveling on the road vary, the load applied to the structure 1 buried under the road also changes with each vehicle passing. Furthermore, since the traffic volume differs depending on the type of road, such as national highways, prefectural roads, and city roads, the number of load repetitions n corresponding to the number of vehicle passages also differs. In such an environment, if the magnitude P of the load per repetition and the number n of load repetitions are set to match the actual environment of the structure 1, a more accurate total crack depth h can be obtained. ｓｕｍ In other words, if the type and number of vehicles traveling on the road can be grasped, the total depth h of the cracks in the structure 1 buried under the road can be calculated. ｓｕｍ This allows for a more accurate calculation of

[0046] Below, methods for determining the types of vehicles traveling on a road and the number of vehicles passing by are described. The first method is a method using a camera. In this method, a camera captures images of the road on which vehicles are traveling. The camera is installed in a position where it can capture images of the road on which structures 1 such as manholes are buried. From the video captured by the camera, it is possible to detect, for example, the size of vehicles passing over the structure 1 per day and the number of vehicles passing over the structure 1 per day. The size of vehicles passing over the structure 1 per day and the number of vehicles passing over the structure 1 per day can be detected from the video captured by the camera by, for example, image recognition using AI (artificial intelligence).

[0047] The weight of a vehicle can be estimated from the size of the vehicle. The weight of the vehicle is the load applied to the structure 1 buried under the road. The number of vehicles passing through the road on which the structure 1 is buried is the number of times the load is applied to the structure 1. Figure 5 is a diagram showing an example of the type, weight, and number of times of passing of a vehicle.

[0048] From Figure 5, the magnitude of the load per load P (= (2000 x 10 + 4500 x 4 + 3000 x 1.5 + 1500 x 0.5) / (2000 + 4500 + 3000 + 1500)) can be calculated. In addition, the number of load repetitions per day n (= 2000 + 4500 + 3000 + 1500) can be calculated.

[0049] In the above-described method using a camera, a camera needs to be installed on the structure 1, and therefore multiple cameras need to be installed in order to acquire data on multiple structures 1. Below, a method will be described for acquiring data on the types of vehicles traveling on the road and the number of passing vehicles for multiple structures 1. This method uses fiber sensing.

[0050] Optical fiber is currently installed throughout the country. Most of the optical fiber is buried underground. Specifically, conduits are installed between manholes, and optical cables run through these conduits and manholes, with the optical fiber housed within the optical cables.

[0051] When a vehicle travels on a road, vibrations are generated. These vibrations are transmitted through the ground and are also transmitted to the optical fiber cable buried in the ground. When the vibrations are transmitted to the optical fiber cable, they are also transmitted to the optical fiber housed within the optical fiber, causing a change in the refractive index within the optical fiber. The change in the refractive index of the optical fiber can be measured remotely. Furthermore, the change in the refractive index can be measured all at once along the length of the optical fiber.

[0052] The heavier a vehicle passes through a road where optical fiber is buried, the greater the vibration of the optical fiber. The vibration of the optical fiber can be detected from changes in the refractive index of the optical fiber. In other words, by remotely measuring the changes in the refractive index, it is possible to detect the weight of vehicles passing through the road and the number of times the vehicle has passed through.

[0053] Since it is possible to measure the change in refractive index all at once along the longitudinal direction of the optical fiber, it is possible to obtain data on the weight of vehicles that have passed through the road and the number of times the vehicles have passed through at the position of the structure 1 by comparing this data with the position information of the structure 1. Once this data is obtained, it is possible to calculate the magnitude P of the load per load and the number of times the load has been applied n, in the same way as in the method using the camera described above.

[0054] As described above, the calculation device 10 according to this embodiment includes a calculation unit 12 and an output unit 13. The calculation unit 12 calculates the depth h of the crack that occurs in the structure 1 due to the first load. １ The depth of the crack in the direction of the crack in the structure 1 is a, and the depth of the crack that occurs in the structure 1 due to the k-1th load on the structure 1 is h. ｋ－１ The depth of the crack that occurs in the structure 1 due to the kth load on the structure 1 is h ｋ Then, the total depth of cracks that occur in the structure 1 due to repeated n loads on the structure 1 can be calculated by the above-mentioned formula (5): ｓｕｍ The output unit 13 outputs the calculated sum hsum of the depth of cracks that will occur in the structure 1 due to the repeated application of the load n times.

[0055] Using the above-mentioned formula (5), the total depth of cracks that occur in the structure 1 due to repeated n loads on the structure 1 is calculated as hｓｕｍ This allows us to reduce the number of analyses using FEM etc. and calculate the total crack depth h ｓｕｍ can be calculated more easily.

[0056] The computing device 10 described above can be realized by a computer 20 shown in FIG. 6. A program for causing the computer 20 to function as the computing device 10 may be provided. The program may be stored on a storage medium or provided via a network. FIG. 6 is a block diagram showing a schematic configuration of the computer 20 functioning as the computing device 10. The computer 20 may be a general-purpose computer, a dedicated computer, a workstation, a PC (Personal Computer), an electronic notepad, or the like. The program instructions may be program code, code segments, or the like for performing necessary tasks.

[0057] 6, the computer 20 includes a processor 21, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 23, a storage 24, an input unit 25, a display unit 26, and a communication interface (I / F) 27. Each component is communicably connected to one another via a bus 29. The processor 21 is specifically a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), a SoC (System on a Chip), or the like, and may be configured with multiple processors of the same or different types.

[0058] The processor 21 is a control unit that controls each component and performs various arithmetic processing. That is, the processor 21 reads a program from the ROM 22 or the storage 24 and executes the program using the RAM 23 as a work area. The processor 21 controls each component and performs various arithmetic processing in accordance with the program stored in the ROM 22 or the storage 24. In this embodiment, the ROM 22 or the storage 24 stores a program for operating the computer 20 as the computing device 10 according to the present disclosure. The processor 21 reads and executes the program, thereby realizing each component of the computing device 10.

[0059] The program may be provided in a form stored on a non-transitory storage medium such as a CD-ROM (Compact Disk Read Only Memory), a DVD-ROM (Digital Versatile Disk Read Only Memory), a USB (Universal Serial Bus) memory, etc. The program may also be provided in a form downloaded from an external device via a network.

[0060] The ROM 22 stores various programs and various data. The RAM 23 temporarily stores programs or data as a working area. The storage 24 is configured with an HDD (Hard Disk Drive) or an SSD (Solid State Drive) and stores various programs including the operating system and various data.

[0061] The input unit 25 includes a pointing device such as a mouse and a keyboard, and is used to input various types of information.

[0062] The display unit 26 is, for example, a liquid crystal display, and displays various information. The display unit 26 may be a touch panel type and function as the input unit 25. The display unit 26 displays, for example, the calculation result of the calculation unit 12 of the sum hsum of the depth of cracks that occur in the structure 1 when the structure 1 is repeatedly loaded n times.

[0063] The communication interface 27 is an interface for communicating with other devices, for example, an interface for a LAN.

[0064] The following additional notes are provided regarding the above-described embodiments.

[0065] [Supplementary Item 1] A calculation device for calculating the depth of a crack that occurs in a structure due to repeated application of the same load to the structure, comprising a control unit, wherein the control unit calculates the depth h of a crack that occurs in the structure due to a first load. １ The depth of the crack in the direction of the crack in the structure is a, and the depth of the crack that occurs in the structure due to the k-1th load on the structure is h. ｋ－１ The depth of the crack that occurs in the structure due to the kth load on the structure is defined as h ｋ Then, the total depth of cracks that occur in the structure due to repeated n loads on the structure can be calculated using the following formula: ｓｕｍ Calculate the total crack depth h calculated ｓｕｍ 3. The computing device configured to output:

[0066] [Supplementary Item 2] In the calculation device according to Supplementary Item 1, the control unit calculates the depth h of a crack that occurs in the structure due to the first load based on the magnitude of the load per load. １ A computing device that calculates.

[0067] [Supplementary Item 3] A calculation method executed by a calculation device that calculates the depth of a crack that occurs in a structure due to repeated application of the same load to the structure, wherein the depth h of a crack that occurs in the structure due to the first load is calculated. １ The depth of the crack in the direction of the crack in the structure is a, and the depth of the crack that occurs in the structure due to the k-1th load on the structure is h. ｋ－１ The depth of the crack that occurs in the structure due to the kth load on the structure is defined as h ｋ Then, the total depth of cracks that occur in the structure due to repeated n loads on the structure can be calculated using the following formula: ｓｕｍ Calculate the total crack depth h calculated ｓｕｍA calculation method that outputs

[0068] [Supplementary Item 4] A non-transitory storage medium storing a program executable by a computer, the non-transitory storage medium storing a program that causes the computer to operate as the computing device according to Supplementary Item 1 or 2.

[0069] Although the above-described embodiments have been described as typical examples, it will be apparent to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, the present invention should not be interpreted as being limited by the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the claims. For example, multiple building blocks shown in the block diagrams of the embodiments can be combined into one, or one building block can be divided.

[0070] 10 Calculation device 11 Input unit 12 Calculation unit 13 Output unit

Claims

1. A calculation device for calculating the depth of cracks that will occur in a structure due to repeated application of the same load to the structure, comprising: a calculation unit that calculates the total crack depth hsum that will occur in the structure due to n repeated loads on the structure using equation (1), where h1 is the depth of the crack that will occur in the structure due to the first load, a is the depth of the crack in the direction of the crack in the structure, hk-1 is the depth of the crack that will occur in the structure due to the k-1th load on the structure, and hk is the depth of the crack that will occur in the structure due to the kth load on the structure; and an output unit that outputs the calculated total crack depth hsum.

2. A calculation device according to claim 1, wherein the calculation unit calculates the depth h1 of a crack that will occur in the structure due to a first load based on the magnitude of each load.

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